The present invention relates to transmission casings for tractors, particularly agricultural tractors equipped with a three point linkage for lifting agricultural implements.
Conventionally, tractors are built around a transmission casing which effectively forms the chassis of the tractor with all other components mounted on it. Tractors are often required to support large loads at the front or rear, for example on the three point linkage of an agricultural tractor, or in the bucket of a tractor loader. This loading, either in front of the front wheels or behind the rear wheels, will be such as to place the upper half of the transmission casing in tension and the lower half in compression. This sort of loading can cause cracks in the upper parts of the transmission casing, and this is the primary factor in determining the maximum safe load which an agricultural tractor can bear on its three point linkage.